Synthesis of shaped-beam radiation patterns using the iterative sampling method

Abstract

The iterative sampling method is introduced for the synthesis of shaped-beam radiation patterns using either line sources or uniformly spaced arrays. Given an original pattern which is some approximation to the desired pattern, a series of correction patterns is added to it. Successive iterations are applied in this manner until the desired performance is achieved. The current distribution is found by a corresponding series of corrections. Several examples show that patterns with either low main-beam ripple and/or low sidelobe level or sharp cutoff from the main beam can be obtained. Unless there is significant ripple or sidelobe improvement, the complexity of the required source current is usually lower than that of the original pattern. For a ten-element array example with \pm 1 -percent error in the current amplitudes and phases about -40 dB, sidelobe and ripple performance was achieved. Furthermore, the iterative sampling method is simple to apply and converges rapidly.